This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. 1. Primary objective of this study is to establish testosterone dose-response relationships in surgically menopausal women with low testosterone concentrations for a range of androgen-dependent outcomes, including sexual function, fat-free mass, thigh muscle strength and leg power, several domains of neurocognitive function, plasma lipids, apolipoproteins and lipoprotein particles, and insulin sensitivity. 2. The secondary objective is to determine the range of testosterone doses and subsequent plasma testosterone concentrations that are associated with improvements in sexual, physical and neurocognitive functions and that can be safely administered to women without significant adverse effects.